This attempts to fix#3942 by way of upgrading `mkdocs` and the associated
dependencies. As I mentioned in the issue, it looks like the hamburger menu
glitch has been fixed in `mkdocs-material` upstream.
**NOTE**
I have been unable to test this change. I currently cannot get past an issue
with `plantuml` when I attempt to run the docs with the suggested:
```sh
make install_venv serve -C docs/mkdocs
```
Here is the issue. I get this error on both MacOS and a Ubuntu machine no
matter which branch I am on. I don't see any mention of anyone else
encountering this in another GitHub issue:
```
Exception: Failed to run plantuml: [Errno 2] No such file or directory: 'plantuml'
make: *** [serve] Error 1
```
But in the spirit of FOSS Friday, I wanted to get a PR up anyways. I was at
least able to determine a cascading set of version number dependencies and I
don't want to lose that effort.
Cheers!
* Add operator<< for json_pointer
* Deprecate json_pointer::operator string_t()
* Update documentation
* Move operator<<(basic_json) example
* Add example
* Add mkdocs-redirects
* Move operator<< and operator>> doc pages out of basic_json/
* Rename JSON pointer operator_string to operator_string_t
* Add unit test
